1. Field of the Invention
One disclosed aspect of the embodiments relates to a photoelectric conversion apparatus, an imaging system, and a method for driving a photoelectric conversion apparatus.
2. Description of the Related Art
For a photoelectric conversion apparatus having an imaging plane formed by a plurality of pixels, a technology called an in-plane synchronized electronic shutter technology in which charge accumulation start times and end times are matched across all the pixels in the imaging plane is known.
Japanese Patent Laid-Open No. 2006-246450 discloses a configuration in which an electric charge accumulation unit is provided separately from a photoelectric conversion unit and most of the electric charge generated in the photoelectric conversion unit is not accumulated in the photoelectric conversion unit but is transferred to the electric charge accumulation unit. After the end of the accumulation period, the electric charge accumulated in the photoelectric conversion unit is transferred to the electric charge accumulation unit and is then further transferred to a floating diffusion unit from the electric charge accumulation unit. A voltage signal corresponding to the amount of electric charge accumulated in the floating diffusion unit is output from the associated pixel.
In the operation disclosed in Japanese Patent Laid-Open No. 2006-246450, the electric charge generated in the photoelectric conversion unit is discharged to a power supply during a period from when electric charge is transferred to the floating diffusion unit to when a voltage signal is output from the associated pixel. Thus, the signal charge generated during the period is lost, and therefore there is a concern that an image with low temporal resolution may be obtained.
The embodiments have been made in light of the foregoing issue.